Various baseball pitches are able to be performed by varying the grip and the throwing motion of the ball, which results in different ball trajectories, speeds, and movements. Common pitches include a two-seam fastball, a four-seam fastball, a slider, a fork ball (split finger), a sinker, a cutter, a curveball, a screwball, a changeup, and a knuckle ball, among others. Learning how to master various pitches is the goal of many aspiring athletes, but the task can be difficult because there are many details to learn and practice, including pitch-specific grips and pitch-specific throwing dynamics.